In various agricultural and other settings, it may be useful to form bales of crop (and other) material. Various machines or mechanisms may be utilized to gather material (e.g., from a windrow along a field) and process it into bales. The formed bales may have various sizes and, in certain applications, may exhibit generally rectangular (or other) cross-sections. In order to create rectangular bales, for example, a square baler may travel along a windrow of cut crop material gathering the material into a generally rectangular baling chamber. A reciprocating plunger or other mechanisms may compress the crop material into bales, which may then be tied with twine or similar material before being ejected from the back of the baler. Such tying may help to ensure that the bales retain their shape after being ejected from the baler.
In order to appropriately tie the formed bales, various balers may include knotter assemblies for tying twine (or similar material). In turn, various knotter assemblies may include tensioning systems for maintaining appropriate tension on the twine during this tying (or during other operations). For various reasons, it may be useful to monitor the operation of certain components of such a tensioning system (or of similar systems included in other machines).
In certain traditional balers, physical flags were attached to various slack arms of knotter assembly such that the flags moved up and down with the slack arms in order to provide an operator of a baler with a visual indicator of the slack arm movement. In certain balers, these physical flags have been replaced with electronic monitoring devices.